Systems, devices, and methods for low-cost respirator evaluation

Abstract

A system for the evaluation of respirator materials includes an aerosolized particle source configured to selectively provide aerosolized particles, a mixing chamber including a drying apparatus, a vacuum source configured to control airflow, an airtight respirator chamber for evaluating respirator materials, a processor, and a memory. The airtight respirator chamber includes a first sub-chamber, a second sub-chamber, a first sensor and a second sensor. The memory includes instructions stored thereon, which when executed by the processor cause the system to: obtain the first signal and the second signal; determine an aerosol filtration efficiency based on a difference between the first signal and second signal; compare the aerosol filtration efficiency to a predetermined threshold; and provide an indication whether the aerosol filtration efficiency is above or below the predetermined threshold.

What is claimed is: 
     
         1 . A system for evaluation of respirator materials, the system comprising:
 an aerosolized particle source configured to selectively provide aerosolized particles;   a mixing chamber including a drying apparatus;   a vacuum source configured to control airflow, wherein the vacuum source includes a venturi vacuum pump uses positive pressure to generate a suction flow;   an airtight respirator chamber including:
 a first sub-chamber; 
 a first sensor configured to generate a first signal indicating an amount of particulate matter upstream from a sample respirator material being evaluated, the first sensor disposed in the first sub-chamber; 
 a second sub-chamber; and 
 a second sensor configured to generate a second signal indicating an amount of particulate matter downstream from the sample respirator material, the second sensor disposed in the second sub-chamber; 
   a processor; and   a memory including instructions stored thereon, which when executed by the processor, cause the system to:
 obtain the first signal and the second signal; 
 determine an aerosol filtration efficiency based on a difference between the first signal and second signal; 
 compare the aerosol filtration efficiency to a predetermined threshold; and 
 provide an indication whether the aerosol filtration efficiency is above or below the predetermined threshold. 
   
     
     
         2 . The system of  claim 1 , wherein the first sensor and the second sensor are configured to measure light scattering. 
     
     
         3 . The system of  claim 1 , wherein a rate of the airflow is about 30 lpm. 
     
     
         4 . The system of  claim 3 , wherein the airtight respirator chamber further includes:
 a first plate;   a second plate configured to be compressed to the first plate; and   a plurality of gaskets disposed on the first plate and the second plate, the plurality of gaskets configured to provide an airtight seal when in compression based on the airflow.   
     
     
         5 . The system of  claim 4 , wherein the aerosolized particle source includes:
 an air source;   a pressure regulator; and   an aerosol generator.   
     
     
         6 . The system of  claim 4 , wherein the drying apparatus includes silica gel. 
     
     
         7 . The system of  claim 4 , wherein prior to testing, the sample respirator material is environmentally conditioned. 
     
     
         8 . The system of  claim 1 , wherein the aerosolized particles include neutralized sodium chloride. 
     
     
         9 . The system of  claim 1 , wherein a size of the aerosolized particles is a geometric mean of about 0.075 μm and a geometric standard deviation of about 2. 
     
     
         10 . The system of  claim 1 , wherein the first sensor and the second sensor are configured to detect aerosolized particles in a range of about 0.3 to about 10.0 μm. 
     
     
         11 . A processor implemented method for evaluating respirator materials, the method comprising:
 supplying aerosolized particles by an aerosolized particle source, wherein the airflow of the aerosolized particles is controlled by a vacuum source, wherein the vacuum source includes a venturi vacuum pump uses positive pressure to generate a suction flow;   drying the aerosolized particles by a mixing chamber including a drying apparatus;   supplying the aerosolized particles to an airtight respirator chamber;   generating, by a first sensor, a first signal indicating an amount of particulate matter upstream from a sample respirator material being evaluated, wherein the first sensor is disposed in a first sub-chamber of the airtight respirator chamber;   generating, by a second sensor, a second signal indicating an amount of particulate matter downstream from the sample respirator material, wherein the second sensor is disposed in a second sub-chamber of the airtight respirator chamber;   determining an aerosol filtration efficiency based on a difference between the first signal and second signal;   comparing the aerosol filtration efficiency to a predetermined threshold; and   providing an indication whether the aerosol filtration efficiency is above or below the predetermined threshold.   
     
     
         12 . The method of  claim 11 , wherein the amount of particulate matter measured by the first sensor and the second sensor are measured using light scattering. 
     
     
         13 . The method of  claim 11 , further comprising:
 controlling rate of the airflow to about 30 lpm.   
     
     
         14 . The method of  claim 11 , wherein the aerosolized particles include neutralized sodium chloride. 
     
     
         15 . The method of  claim 11 , wherein the first sensor and the second sensor are configured to sense aerosolized particles with a geometric mean of about 0.075 μm and a geometric standard deviation of about 2. 
     
     
         16 . The method of  claim 11 , wherein the first sensor and the second sensor are configured to detect particles in a range of about 0.3 to about 10.0 μm. 
     
     
         17 . The method of  claim 11 , further comprising:
 manually compressing the sample between a first plate and a second plate of the airtight respirator chamber, wherein a plurality of gaskets are disposed on the first plate and the second plate, the plurality of gaskets configured to provide an airtight seal when in compression based on the airflow.   
     
     
         18 . The method of  claim 17 , wherein the drying apparatus dries the aerosolized particles using silica gel. 
     
     
         19 . The method of  claim 17 , further comprising, prior to testing, environmentally conditioning the sample. 
     
     
         20 . A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method for evaluation of respirator materials, the method comprising:
 supplying aerosolized particles by an aerosolized particle source;   drying the aerosolized particles by a mixing chamber including a drying apparatus;   controlling airflow of the aerosolized particles by a vacuum source, wherein the vacuum source includes a venturi vacuum pump uses positive pressure to generate a suction flow;   supplying the aerosolized particles to an airtight respirator chamber;   generating, by a first sensor, a first signal indicating an amount of particulate matter upstream from a sample respirator material being evaluated, wherein the first sensor is disposed in a first sub-chamber of the airtight respirator chamber;   generating, by a second sensor, a second signal indicating an amount of particulate matter downstream from the sample, wherein the second sensor is disposed in a second sub-chamber of the airtight respirator chamber;   determining an aerosol filtration efficiency based on a difference between the first signal and second signal;   comparing the aerosol filtration efficiency to a predetermined threshold; and   providing an indication whether the aerosol filtration efficiency is above or below the predetermined threshold.